Official stats say just 257,000 came from the EU sparking controversy among MPs.

MINISTERS were last night accused of a migration “cover-up” — as it was claimed true figures may be more than double official stats.

Some 257,000 EU nationals were said to have arrived last year, but it emerged 630,000 registered to work. One expert said the Government appeared to be “deliberately keeping voters in the dark” to boost its chances in the In/Out referendum.

The Government yesterday revealed 323,000 more people arrived than left in the year to September, up 31,000.

But separate data showed 630,000 got a National Insurance number last year – including 170,000 Romanians.

Jonathan Portes, from UK in a Changing Europe, said: “Immigration may have been considerably understated.”